Yes you could program anything in the language, just like you could programming anything in any language. But he's designing the language for video game development. The whole reason he's making it is for videos specifically, and he's been very explicit that he does believe that a language should not try to be designed for use in every application.
[0]: https://www.youtube.com/playlist?list=PLmV5I2fxaiCKfxMBrNsU1...
If other domains benefit from that, he's not going to actively bar them from using his language, but he also won't give them much consideration.
But:
1) Lots of things things have high overlap with fast/LL languages.
2) I imagine there are nice returns to focusing the language on a specific use-case, even more so when the core developers are not actively using it for the other use cases (I doubt he or his team will be doing embedded work anytime soon).
The one part I disagree with is:
> A lot of these things do find some modest niche to survive in. But none really take over the world as originally forecast by the hype wave.
One of Blow's critique of C++ is specifically that it's trying to be the everything language. Jai's goal is to be for video game development, and that's it. Not for embedded systems, not kernels, not drivers, not high performance computing, not operating systems. Just video games.